package server_test

import (
	"context"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strconv"
	"testing"

	"github.com/getsentry/sentry-go"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"sneak.berlin/go/webhooker/internal/config"
	"sneak.berlin/go/webhooker/internal/server"
)

// The link back the error page offers: to the webhook list for a
// signed-in user, to sign-in for anyone else.
const (
	backToWebhooks = `<a href="/hooks" class="btn-secondary">` +
		`Back to webhooks</a>`
	backToSignIn = `<a href="/pages/login" class="btn-primary">` +
		`Sign in</a>`
)

// assertErrorPage checks that w is the error page for status, in the
// normal layout, offering link.
func assertErrorPage(
	t *testing.T,
	w *httptest.ResponseRecorder,
	status int,
	link string,
) {
	t.Helper()

	body := w.Body.String()

	assert.Equal(t, status, w.Code)
	assert.Equal(
		t, "text/html; charset=utf-8", w.Header().Get("Content-Type"),
	)
	assert.Equal(t, "no-store", w.Header().Get("Cache-Control"))
	assert.Contains(t, body, `<nav class="app-bar"`)
	assert.Contains(
		t, body, strconv.Itoa(status)+" "+http.StatusText(status),
	)
	assert.Contains(t, body, link)
}

func TestErrorPage_DeletedWebhook(t *testing.T) {
	t.Parallel()

	env := newTestEnv(t)

	userID, _ := env.seedUser(t, "owner", "somepassword")
	cookies := env.authCookies(t, userID, "owner")

	wh := env.seedWebhook(t, userID)
	require.NoError(t, env.db.DB().Delete(wh).Error)

	w := env.get("/hook/"+wh.ID, cookies)

	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
}

func TestErrorPage_DeletedTarget(t *testing.T) {
	t.Parallel()

	env := newTestEnv(t)

	userID, _ := env.seedUser(t, "owner", "somepassword")
	cookies := env.authCookies(t, userID, "owner")

	wh := env.seedWebhook(t, userID)
	tgt := env.seedTarget(t, wh.ID)
	require.NoError(t, env.db.DB().Delete(tgt).Error)

	w := env.get(
		"/hook/"+wh.ID+"/targets/"+tgt.ID+"/edit", cookies,
	)

	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
}

// TestErrorPage_ShowsNoNotice pins that a notice code in the URL of a
// page that fails is not shown above the error.
func TestErrorPage_ShowsNoNotice(t *testing.T) {
	t.Parallel()

	env := newTestEnv(t)

	userID, _ := env.seedUser(t, "owner", "somepassword")
	cookies := env.authCookies(t, userID, "owner")

	w := env.get("/hook/no-such-webhook?notice=webhook-saved", cookies)

	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
	assert.NotContains(t, w.Body.String(), "Webhook saved.")
}

func TestErrorPage_UnknownPath(t *testing.T) {
	t.Parallel()

	env := newTestEnv(t)

	userID, _ := env.seedUser(t, "owner", "somepassword")
	cookies := env.authCookies(t, userID, "owner")

	assertErrorPage(
		t, env.get("/no-such-page", nil),
		http.StatusNotFound, backToSignIn,
	)

	// Outside every route group there is no form token, so the
	// page leaves out the logout form rather than offer one that
	// would be refused.
	w := env.get("/no-such-page", cookies)
	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
	assert.NotContains(t, w.Body.String(), `action="/pages/logout"`)

	// Inside a route group the page has a token, and logout works.
	wh := env.seedWebhook(t, userID)
	w = env.get("/hook/"+wh.ID+"/no-such-page", cookies)
	assertErrorPage(t, w, http.StatusNotFound, backToWebhooks)
	assert.Contains(t, w.Body.String(), `action="/pages/logout"`)
}

func TestErrorPage_BadCSRFToken(t *testing.T) {
	t.Parallel()

	env := newTestEnv(t)

	form := url.Values{}
	form.Set("username", "someone")
	form.Set("password", "irrelevant")
	form.Set("csrf_token", "not-a-token")

	assertErrorPage(
		t, env.post("/pages/login", form, nil),
		http.StatusForbidden, backToSignIn,
	)

	userID, _ := env.seedUser(t, "owner", "somepassword")
	cookies := env.authCookies(t, userID, "owner")
	wh := env.seedWebhook(t, userID)

	edit := url.Values{}
	edit.Set("name", "renamed")

	assertErrorPage(
		t, env.post("/hook/"+wh.ID+"/edit", edit, cookies),
		http.StatusForbidden, backToWebhooks,
	)
}

// TestErrorPage_PanicOnAdminPage sends a panicking handler in an
// admin page route group through the real router, with error
// tracking on: the client gets the 500 error page, and the tracker
// still gets the panic, once. The same panic outside the admin page
// route groups keeps the plain 500.
func TestErrorPage_PanicOnAdminPage(t *testing.T) {
	t.Parallel()

	env := newTestEnv(t)

	transport := &captureTransport{}

	opts := server.SentryClientOptionsForTest(
		"https://public@sentry.invalid/1", "webhooker-test",
	)
	opts.Transport = transport

	client, err := sentry.NewClient(opts)
	require.NoError(t, err)

	serve := func(router http.Handler, path string) *httptest.ResponseRecorder {
		req := httptest.NewRequestWithContext(
			sentry.SetHubOnContext(
				context.Background(),
				sentry.NewHub(client, sentry.NewScope()),
			),
			http.MethodGet, path, nil,
		)

		w := httptest.NewRecorder()
		router.ServeHTTP(w, req)

		return w
	}

	w := serve(
		server.NewRouterWithPageProbeForTest(
			env.log.Get(), env.cfg, env.mw, env.hnd,
			true, panicProbeHandler,
		),
		server.PageProbePattern,
	)
	assertErrorPage(t, w, http.StatusInternalServerError, backToSignIn)

	w = serve(
		server.NewRouterWithProbeForTest(
			env.log.Get(), env.cfg, env.mw, env.hnd,
			true, panicProbeHandler,
		),
		server.ProbePattern,
	)
	assert.Equal(t, http.StatusInternalServerError, w.Code)
	assert.Equal(t, "Internal Server Error\n", w.Body.String())

	require.Len(t, transport.events, 2)

	for _, event := range transport.events {
		assert.Contains(t, marshalEvent(t, event), panicProbeMarker)
	}
}

// TestErrorPage_ReceiverStaysPlain pins that the error page is for
// the web UI only: a sender posting to an entrypoint that does not
// exist still gets the plain-text answer.
func TestErrorPage_ReceiverStaysPlain(t *testing.T) {
	t.Parallel()

	// newTestEnv leaves the receiver rate limit at zero, which
	// refuses every request before it reaches the receiver.
	env := newTestEnvWithConfig(t, &config.Config{
		DataDir:           t.TempDir(),
		Environment:       config.EnvironmentDev,
		ReceiverRateLimit: 10,
	})

	w := env.post(
		"/h/0b8f3c1e-7d2a-4e6b-9f15-3a9c2d4e6f70", url.Values{}, nil,
	)

	assert.Equal(t, http.StatusNotFound, w.Code)
	assert.Equal(t, "404 page not found\n", w.Body.String())
}